1. Field of the Invention
This invention relates generally to devices for tuning snow skis and, more particularly, to a device adapted to automatically bevel the metal edges of snow skis in direct corrolation with the width of the ski.
2. Description of the Prior Art
Snow skis that are utilized for alpine skiing are made from various materials, including wood, plastic, fiberglass and the like but, regardless of the material from which the ski is made, they all contain metal edges extending along the length of the ski on opposite sides of the bottom surface of the ski in coplanar relationship therewith. The metal edges when fabricated into the ski have an outer edge forming a right angle with the vertical side walls of the ski, but if this right angle were to extend the entire length of the ski, it would be very difficult to turn the skis, as the right angle on the edge inhibits the turning of the ski and encourages the ski to tract straightforwardly. Accordingly, it is desirable to facilitate turning of the skis to place a slight bevel on the metal edges so that the bottom surface of the metal edge forms a slight angle, sometimes up to 2 degrees, relative to the bottom surface of the ski.
It is desirable to have the maximum bevel near the leading and trailing ends of the ski to reduce the resistance to lateral movement at these locations so that the skis are easier to turn. A very minor bevel is desirable near the longitudinal center of the ski so that it is easy to carve turns and get a firm grip on the snow for control during a turn.
Alpine snow skis have another similar characteristic in that the leading and trailing ends of the skis are wider than the longitudinal center of the ski. Accordingly, Applicant has concluded that the bevel placed on the metal edges can have a direct relationship to the width of the ski so that the greater the width, the greater the bevel should be. Accordingly, near the leading and trailing ends of the ski, where it is widest, the bevel is the greatest so as to enable the skis to be turned easily. Similarly, at the longitudinal center of the ski, where the ski is narrowest, the bevel is the smallest to enable the desired carving of the ski through turns.
Most alpine skis are fabricated with different materials which are bonded together with various resins or other bonding mediums, and these bonding mediums typically take weeks to cure. For this reason, the manufacturers of alpine snow skis typically ship the skis to retail locations before the bonding medium has totally cured. Accordingly, when the skis finally reaches the retail destination or shortly thereafter, and the bonding medium has cured, the various bonded components of the skis may have contracted during the curing process so that the bottom surface of the skis are not smooth, as desired, and may not be coplanar with the metal edges. Accordingly, after the skis have reached the retail destination, it is necessary to tune the skis by grinding the bottoms of the skis so that they are smooth, as desired, and then filing the metal edges until the bottom surfaces thereof are substantially coplanar with the bottoms of the skis. The metal edges should be beveled during this same tuning process so as to increase the angle between the bottom surfaces of the metal edges and the bottom surfaces of the skis near the leading and trailing ends of the skis so that the skis will properly perform for the ultimate purchaser.
Traditionally, the process of grinding the desired bevel into the bottom surface of the metal edges has been performed by hand, and typically by a worker at a retail shop who is frequently not well trained to place the desired bevel on the metal edges. Even a very skilled and experienced worker in this field has trouble with a hand file in placing a uniform bevel on both sides of the ski due to the fact that it is a manual process subject to human error and is frequently performed solely from feel developed through experience. It has been found that it requires a skilled worker three or four months to train a new worker, and even after months of training, the tuning process takes a considerable amount of time. Further, due to the fact that the skis cannot be tuned at the manufacturing site because they are usually shipped before the bonding medium has completely cured, it is a natural consequence that the tuning of skis, including the beveling of the metal edges, is done by a large number of people resulting in a lack of uniformity from retail location to retail location. Accordingly, the ultimate purchaser of the skis does not get a predictable product.
It is to overcome the above-noted problems that the present invention has been developed.
The prior art known to Applicant discloses several systems for automatically sharpening the metal edges of snow skis, but in each instance, the device is limited to a system which grinds a right angle to the edge of the ski and makes no provision for beveling the edge. Examples of such prior art systems are disclosed in U.S. Pat. No. 3,159,951, issued to Windbauer; U.S. Pat. No. 3,585,760, issued to Richmond; U.S. Pat. No. 3,899,942, issued to Bradbury; and U.S. Pat. Nos. 3,412,508 and 3,512,308, each issued to Schell, Jr.
U.S. Pat. No. 4,442,636, issued to Obland, discloses a hand-operated device for simultaneously sharpening both edges of a ski, but again, the edges are sharpened at right angles, and there is no suggestion of means for beveling the edges of the ski.
U.S. Pat. No. 4,030,382, issued to Nilsson, et al., discloses a device for sharpening the steel edges of a ski and includes an embodiment wherein the sharpening element of the device can be inclined so that an angle less than 90 degrees can be imparted to the metal edge establishing a bevel as opposed to a right-angled edge on the ski. This device, however, has no suggestion of relating the bevel to the width of the ski.